Cermark Alley Cat Takeoff Problem
08-12-2009 | 09:42 AM
#1
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From: Cambria, CA,
Cermark Alley Cat Takeoff Problem
The Cermark Alley Cat 1/4 scale has a tiny rudder and a short tail moment. That, coupled with torque, makes it very hard to take off down a narrow road lined with bushes and weeds. It quickly heads for the side of the road and no correction will change its mind. Any experience with it?
08-12-2009 | 12:47 PM
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From: Poolesville, MD
RE: Cermark Alley Cat Takeoff Problem
I don't have that plane but I do have a couple of racers.
What you describe does not sound unusual.
Here are a few things you can do to fix this:
- Increase the height of the tail.
In other words, adjust the rear wheel, so that the plane sits more level. This will lessen the left yaw at run-up effect.
- Toe-in the wheels.
Toe in both wheels equally. This prevents the plane from yawing away from you as one wheel gets light due to airspeed.
- Adjust plane tailwheel so that plane tracks slightly to right.
Push the plane forward on the ground, with the stick centered.
The plane should track turning slightly to the right, this helps offset the left yaw at runup.
- Increase right thrust a degree.
Do this in small increments, add a shim or washers to increase right thrust. Watch how the plane does in the air as well.
What you describe does not sound unusual.
Here are a few things you can do to fix this:
- Increase the height of the tail.
In other words, adjust the rear wheel, so that the plane sits more level. This will lessen the left yaw at run-up effect.
- Toe-in the wheels.
Toe in both wheels equally. This prevents the plane from yawing away from you as one wheel gets light due to airspeed.
- Adjust plane tailwheel so that plane tracks slightly to right.
Push the plane forward on the ground, with the stick centered.
The plane should track turning slightly to the right, this helps offset the left yaw at runup.
- Increase right thrust a degree.
Do this in small increments, add a shim or washers to increase right thrust. Watch how the plane does in the air as well.
08-31-2009 | 03:10 PM
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From: Cambria,
CA
RE: Cermark Alley Cat Takeoff Problem
Thank you for all the suggestions, I have been away and just read your response. I will try each of them, especially the need for toe-in, something I learned from my Lil Toni ages ago. It roars left with with power applied, but I rotate within 10'. The YS110 and 13x13 facilitate that, but the puny OS60 is no match.
Thanks again.
Thanks again.
This is the drawback of having to much torque. You have to ease in the throttle with liberal amounts of rudder.
09-02-2009 | 08:51 PM
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From: Panama City Beach,
FL
RE: Cermark Alley Cat Takeoff Problem
Try shoving the throttle stick to the upper right corner of the transmitter. This will give you full throttle and full right rudder to counteract all the torque you just imposed on the airplane. When the plane starts heading to the right as speed builds up, move the stick back toward the center until it stops turning right. This sounds crazy but it works. I've taught many people to takeoff taildraggers using this method. After 2-3 attemps they're takeoff rolls are arrow straight. 
09-03-2009 | 02:13 AM
#6
RE: Cermark Alley Cat Takeoff Problem
ORIGINAL: Yak18
Try shoving the throttle stick to the upper right corner of the transmitter. This will give you full throttle and full right rudder to counteract all the torque you just imposed on the airplane. When the plane starts heading to the right as speed builds up, move the stick back toward the center until it stops turning right. This sounds crazy but it works. I've taught many people to takeoff taildraggers using this method. After 2-3 attemps they're takeoff rolls are arrow straight.
Try shoving the throttle stick to the upper right corner of the transmitter. This will give you full throttle and full right rudder to counteract all the torque you just imposed on the airplane. When the plane starts heading to the right as speed builds up, move the stick back toward the center until it stops turning right. This sounds crazy but it works. I've taught many people to takeoff taildraggers using this method. After 2-3 attemps they're takeoff rolls are arrow straight.
I dont reccomend shoving any stick on take off....You need to gradually give it throttle, and at the same time gradually correct the torque with enough rudder to counter act it
09-07-2009 | 04:16 PM
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From: Panama City Beach,
FL
RE: Cermark Alley Cat Takeoff Problem
ORIGINAL: MetallicaJunkie
-1
I dont reccomend shoving any stick on take off....You need to gradually give it throttle, and at the same time gradually correct the torque with enough rudder to counter act it
ORIGINAL: Yak18
Try shoving the throttle stick to the upper right corner of the transmitter. This will give you full throttle and full right rudder to counteract all the torque you just imposed on the airplane. When the plane starts heading to the right as speed builds up, move the stick back toward the center until it stops turning right. This sounds crazy but it works. I've taught many people to takeoff taildraggers using this method. After 2-3 attemps they're takeoff rolls are arrow straight.
Try shoving the throttle stick to the upper right corner of the transmitter. This will give you full throttle and full right rudder to counteract all the torque you just imposed on the airplane. When the plane starts heading to the right as speed builds up, move the stick back toward the center until it stops turning right. This sounds crazy but it works. I've taught many people to takeoff taildraggers using this method. After 2-3 attemps they're takeoff rolls are arrow straight.
I dont reccomend shoving any stick on take off....You need to gradually give it throttle, and at the same time gradually correct the torque with enough rudder to counter act it
09-07-2009 | 08:34 PM
#8
RE: Cermark Alley Cat Takeoff Problem
[youtube][/youtube]
http://www.youtube.com/watch?v=baQ0MqFnHg0
http://www.youtube.com/watch?v=baQ0MqFnHg0
